American Sports Data Inc. categorizes sports as follows:

FITNESS

General
Aerobics (High-Impact)
Aerobics (Low Impact)
Aerobics (Step)
Aquatic Exercise
Calisthenics
Cardio Kickboxing
Fitness Biking
Fitness Walking
Gymnastics
Running/Jogging
Swimming (Laps/Fitness)
Stretching
Yoga/Tai Chi
Pilates Training

Equipment Exercise
Barbells
Dumbbells
Hand Weights
Weight/Resistance Machines
Multi-Purpose Home Gyms
Abdominal Machines
Rowing Machines
Upright Bikes (Regular)
Upright Bikes (Spinning)
Recumbent Bikes
Stair-Climbers/Steppers
Treadmills
Elliptical Motion Trainers
Nordic/Cross-Country Ski Machines
Aerobic Riders

RECREATIONAL

Team Sports
Baseball
Basketball
Cricket
Cheerleading
Football (Touch)
Football (Tackle)
Ice Hockey
Field Hockey
Lacrosse
Rugby
Soccer (Outdoor)
Soccer (Indoor)
Softball (Slow-Pitch)
Softball (Fast-Pitch)
Ultimate Frisbee
Volleyball (Grass)
Volleyball (Sand/Beach)
Water Polo
Volleyball (Court)

Racquet/Paddle Sports
Badminton
Racquetball
Tennis
Deck Tennis
Squash
Paddleball

Skating Sports
Ice Skating
Roller Hockey
Roller Skating (2x2 Wheels)
Roller Skating (In-Line Wheels)
Scooter Riding (Non-Motorized)
Skateboarding

Indoor Games
Billiards/Pool
Bowling
Table Tennis
Darts

Other Recreational
Sports/Activities

Bicycling (Recreational)
Bicycling (BMX)
Double Dutch
Golf
Minature Golf
Handball
Walking (Recreational)
Paintball
Boules (Boccie)
Curling
Croquet
Horseshoes
Shuffleboard

Personal Contact Sports
Boxing
Martial Arts
Wrestling

OUTDOORS

Camping (Tent)
Camping (R.V.)
Backpacking
Fishing (Fly)
Fishing (Other Freshwater)
Fishing (Saltwater)
Clamming
Hiking (Day)
Hiking (Overnight)
Horseback Riding
Mountain Biking
Mountaineering
Mountain/Rock Climbing
Ice Climbing
Artificial Wall Climbing
Spelunking
Trekking
Trail Running
Outdoor Water:
Canoeing
Kayaking
Rafting

Water Sports
Boardsailing//Windsurfing
Diving (platform/springboard)
Jet Skiing/Personal Watercraft
Sailing
Scuba Diving
Snorkeling
Surfing
Swimming (Recreational)
Wakeboarding
Water Skiing

Air Sports
Bungee jumping
Hot air ballooning
Paragliding
parasailing
skydiving

Shooting Sports
Archery
Hunting (Shotgun/Rifle)
Hunting (Bow)
Shooting (Sporting Clays)
Shooting (Trap/Skeet)
Target Shooting (Rifle)
Target Shooting (Handgun)

Snow Sports
Skiing (Cross-Country)
Skiing (Downhill)
Snowboarding
Snowmobiling
Snowshoeing

Observation - Collecting
Bird Watching/Birding
Whale Watching
Shell collecting/shelling

Source: American Sports Data Inc. americansportsdata.com with additions.
MOTORIZED SPORTS
OFF-ROAD/OFF-HIGHWAY
4WD/4x4/Four Wheel Drive
  (SUV, Jeep)
ATV/Quad
  (all-terrain vehicle)
Dirt Bike/motocross
Snowmobiling
ROAD - TRACK
Sportscar racing
motorcycle racing
Go-cart
AIR/SEA
Power Boat (cruiser)
Power Boat (runabout)
Power Boat (pontoon, house)
Personal Watercraft
  (Jet Ski, Waverunner®, Sea-Doo®)
Airplane
Ultralight
last updated 12 July 2005